TAMAYA-277: Try different way to launch sonarcloud integration

Direct mvn call did not seem to work althout token
is introduced as environment variable.
diff --git a/.travis.yml b/.travis.yml
index 45b6530..0b865de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -18,5 +18,5 @@
     organization: "apache" 
 script:
   # other script steps might be done before running the actual analysis
-#  - sonar-scanner
-  - mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent install sonar:sonar
+  - sonar-scanner
+#  - mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent install sonar:sonar